Fuse device



Oct. 11, 1938. B. R. HERMA N 7 2,133,139

FUSE DEVICE Filed Nov. 24, 1957 Inventor": 55 Benjamin R. Hermahn,

is Attorney.

Patented on. 11, 1938 PATENT OFFICE FUSE DEVICE Benjamin B. Hermann,

Lancsborough, Man, as-

signonto General Electric Company, a corporation of New York ApplicationNovember 24, 1937, Serial No. 176,271

12 Claims.

The present invention relates to fuse devices and has for an object theprovision of a fuse device of simple and low cost design having improvedmounting means particularly suited for installation of the fuse deviceon, a bushing supported terminal stud of a transformer or like piece ofelectric apparatus.

A further object of the invention is the provision of a fuse device ofimproved fuse link tensioning and retracting means and of improvedsafety means for preventing swinging of a ruptured fuse link intoshort-circuiting engagement with the live parts of a fuse installation.

Qther objects and the details of that which-I believe to be novel and myinvention will become apparent from the'followlng description and the.

claims appended thereto taken in conjunction with the accompanyingdrawing in which Fig. 1

shows a side-view of an exemplary form of fuse device embodying thepresent invention; Fig. 2 IS a view looking down on the fuse-device ofFig. 1; Fig. 3 shows the positions of certain parts of the fuse afteroperation of the fuse link therein;

Fig. 4 is an exploded view of a detail feature of the invention; andFigs. 5 and 6 are views respectively from two different sides of aportion of a fuse device embodying a modification of the in- .vention.

Referring to the drawing, i0 designates a fuse 0 holder oftheexpulsion'type which includes an insulating fuse tube open atitslower end and closed at its upper end by means of a removable terminal,cap ll. Mounted adjacent the upper end of the fuse holder inelectrically' conductive relation with cap ll isa metallic collar I2.which and as a mounting bracket for the fuse holder and which includesan intermediate socket portion ll having an opening I! for receiving the0 lower open end of the fuse holder, the holderbe-' ing secured-in thesocket opening in any suitable manner, as by means of a pin i6 whichextends through the socket portion into engagement with the side of thefuse holder. Projecting outwardly from one side of the socket portion I4is a springy mounting arm I! provided'adjacent its outer end with anattachment portion 10 which includes a socket opening 2] for receiving aterminal stud 22 of a transformer or like piece of electric apparatus.As shown in the drawing, the

attachment portion 20 of the arm is adapted to rest upon the upper endof the bushing 23 which supports the terminal stud and to be tightlyclamped thereon by means of nut 24. The socket portion I l of thebracket is so arranged that the extended axis of socket opening l5 liesin a plane with and intersects the extended axis of the attachmentsocket opening it. Thus, fuse holder I0 is maintained in a positionwherein its upp portion is tilted toward the supporting terminal stud 22while'the lower open end of the fuse holder is directed away from theterminal stud and insulator bushing 23. As a result of this expedient,arc gases discharged from fuse holder l0 will be directed away frominsulator bushing 23 so. as to prevent damage thereto and also will bedirected awayfrom conducting parts of the electric apparatus of whichterminal stud 22 forms a part to prevent arc-over between suchconducting parts.

The mounting bracket has a second arm 21 which projects outwardly fromthe socket For-- tlon ll on the opposite side thereof from mounting armll. Intermediate the outer end of arm 21 and socket portion I4 is awinged clamping screw 28 for securing tothe arm the outward projectinglower end 28 ofv a fuse link disposed in fuse holder 10, the other endof which fuse link is anchoredin the upper end of the fuse holder andelectrically connected with terminal cap II. In order normally totension the fuse link there is provided a metallic springstrip 30 oneend of which is fastened to a collar 3| mounted on fuse holder ill ininsulated spaced relation to the socket portion ll of .the terminalmounting bracket and the other end of which spring strip has shock 32for quick releasable engagement with the outwardly extending portion 29of the fuse link intermediate the lowerend of the fuse holder and clamp28. Spring strip 30 is reinforced by spring strlps a and 34 disposed respectively on opposite sides thereof and the spring strip it normally isbowed, as shown in Fig. l, to tension the fuse link in the fuse holder.Upon rupture of the fuse link due to current overload. the spring strip30 quickly withdraws the lower portion of the ruptured fuse link from-'the fuse holder to aidin extinction of the are formed between theruptured ends of the fuse link upon fuse operation. The expulsion forceof the gases generatedin the fuse holder upon fuse operation also tendsto eject the lower end of the ruptured fuse link from the holder. Aswill be seen best from Fig. 2. the bowed springstrip, 30 extends"substantially parallel with a vertical plane extending through arm 21.As a result of this expedient and the expulsion force of the gasesdischarged from the lower end of the fuse holder, the free end of thewithdrawn portion of the ruptured fuse link is caused to swing outwardlyabout clamp 28 and away from the bushing supported terminal stud so asto prevent short-circuiting engagement of the free end of the withdrawnportion with conducting parts of the electric apparatus of whichterminal stud 22 forms a part. In order to prevent swinging of the freeend of the withdrawn portion of the fuse link upwardly intoshort-circuiting engagement with the terminal collar l2, terminal arml3, or other live parts at the upper end of in Fig. 3, and the outwardlyprojecting spaced arms 31 of the snubbing element insure against theescaping sideways of the withdrawn fuse link portion from the snubbingelement. With the arrangement described, the distance from the snubbingelement, which projects outwardly beyond clamp 28, is greater than thelength of the withdrawn portion of the fuse link even though the fuselink ruptures at a point adjacent the upper end of the fuse holder.Also, as the withdrawn fuse link portion wraps around the snub-' bingelement, it becomes disengaged from the hook 32 of spring strip 30 andthe spring strip is then electrically isolated from all conducting partsof the fuse device and extends outwardly, as indicated in Fig. 3, to.give clear indication of fuse operation. The electric isolation of thespring strip from the lower terminal member insures against arcing tothe spring strip or to hook 32 during ejection of a ruptured fuse linkso that the spring strip is not called upon to carry heavy currentswhich might cause the spring strip to lose its springiness.

It is desirable to provide for selective positioning of the fuse deviceon the supporting terminal stud 22 and at the same time to insureagainst movement of the fuse device out of the selected position. Tothis end the attachment portion 20 of arm I! is provided with aplurality of slots 40 which communicate with and extend radially of thesocket opening 2 I. These slots are arranged in pairs with the slots ofeach pair disposed diametrically opposite each other and with the pairsangularly spaced apart. When the mounting bracket is mounted on thesupporting terminal stud 22, it is turned into a desired positionwherein a predetermined one of the pairs of slots 4!! register with atransverse slot 4| in the terminal stud. Then, in order to maintain thisselected position, a keeper element 42 is placed in the selected pair ofslots 40 and the transverse slot 4|. This keeper element is ofapproximately U-shape having a transverse portion 43 adapted to seat inslot 4| with the outer ends of I this transverse portion extending intodiametrically opposite slots 40, and having also spaced apart arms 44bent inwardly and then upwardly, as shown in Fig. 4, to be receivedinthe bore of nut 24. The arms 44 may be inserted in the bore of the nutand the upper ends of the arms bent outwardly so as to make the keeper apart of the nut assembly. With the arrangement illustrated, wherein twopairs of slots 40 are provided, the mounting bracket may be supported onterminal stud 22 in anyone of four different positions angularlydisplaced 90 apart, two of these positions being indicated respectivelyin solid and broken lines in Fig. 2. It will be understood of coursethat more than two pairs of slots 40 may be employed if it is desired toprovide for more than four possible positions.

In Figs. 5 and 6 is illustrated an embodiment of the spring retractingand snubbing feature of my invention which is particularly adapted foruse with line suspension type fuse cutouts. In this latter embodiment,there is mounted on the lower end of the fuse holder Ill a metallicterminal collar d5 which has projecting outwardly from one side thereofan arm 46 provided with any suitable form of clamping means, indicatedat M, for securing a line connection lead 48 thereto. Projectingoutwardly from the opposite side of terminal collar 45 isan arm 50provided with a winged clamp screw 5! for anchoring thereto theoutwardly extending portion 29 of a fuse link, the other end of whichfuse link is connected with a terminal cap, as previously described inconnection with the embodiment -of Figs. 1 to 3. Also mounted on'thelower end of fuse holder ill, but in insulated spaced relation toterminal collar 45 is a second collar 52 which has an arm 53 projectingoutwardly and downwardly therefrom so that the outer end of the arm isdisposed to the side of and below the lower end of the fuse holder, asshown in Fig. 5.

a coiled spring strip 55. The other end of spring "wardly, it'engagesthe transversely extending portion 54 of arm 53, and is snubbed'by thisportion 54 so that the free end of the withdrawn fuse link portion isprevented from swinging upwardly about clamp 5| into short-circuitingengagement with live parts at the upper end of the fuse holder. 'Also,as in the embodiment of Figs. 1 to 3, the withdrawn fuse link portionbecomes disengaged from hook 56 as it swings outwardly so that springstrip is then electrically isolated from all conductive parts of thefuse device and the spring strip projects outwardly to give a clearindication of fuse link operation.

It will be evident that my invention is -not limited to the specificdetails of the embodiments illustrated and that various modificationswell within the range of mechanical skill may be made to adapt theinvention to various conditions met with in actual practice.

modifications as fall within the true spirit and scope of my presentinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In a fuse device, the combination with a fuse holder of the expulsiontype havingan open Hence, it is intended to cover by the appended claimssuch end for, the discharge of gases therefrom, of an electricallyconductive bracket for mounting said holder on a terminal stud of atransformer or like support, said bracket having a socket for receivingsaid holder and having also a relatively springy arm extending outwardlyfrom said holder with a second socket adjacent the outer end of the armfor receiving a supporting terminal stud, said first socket beingarranged so as to support said holder tilted substantially toward theouter end of said arm with the said discharge end of the holder directedaway from said outer end of the arm.

2. In a fuse device, the combination with a fuse holder of the expulsiontype having an open end for the discharge of gases'therefrom, of meansfor mounting said holder on a terminal stud having a transverse slot,said means including an electrically conductive bracket having a socketopening adapted to receive a slotted terminal stud, said bracket beingprovided also with a plurality of slots communicating with and extendingradially of said socket opening'in angularly spaced relationship to eachother, and a keeper element adapted to be placed in selected ones ofsaid slots andto extend through a transverse slot in a terminal studupon which said bracket is mounted in order to maintain said bracket inselected positions and prevent rotation of the bracket about thesupportingterminal stud.

3. In a fuse device, a fuse holder having a gas discharge opening at oneend, an electrically conductive mounting bracket secured to said holderand having an outwardly projecting arm with means adjacent the outer endthereof for attachment to a support for said holder, said bracket beingarranged to support said'holder with the said gas disbhargeend thereofdirected away from the attachment end of said arm, clamping means forsecuring to said bracket one end of a fuse link extending .out of saidone end of the holder, and a spring device arranged to be connected witha fuse link in said holder for normally tensioning the fuse link, saidspring device being operative upon fuse link rupture quickly to withdrawa portion of the ruptured manner to cause the withdrawn fuse linkportion to swing away from the said outer attachment end of said arm.

4. In a fuse device, a fuse holder, .an electrically conductive mountingbracket secured to said holder adjacent one end thereof, means forsecuring to said bracket one end of a fuse link extending from said oneend of the fuse holder,

said bracket having a pair of arms projecting outwardly respectively indifferent directions from said fuseholder and one of said arms havingmeans for attachment thereof to a support for said fuse holder, a springdevice arranged to be connected with the end of a fuse link extendingfrom said one end of the fuse holder for effecting quick withdrawal of aportion of the fuse anchored tov the other of said terminals, fuse linktensioning and retracting spring means connected with said other end ofthe fuse link and operative upon fuse link rupture to eifect quickwithdrawal of a portion of the fuse link in a manner to cause saidwithdrawn portion to swing about its anchoring point on said otherterminal, and snubbing means arranged to intercept, the said withdrawnfuse link portion to-prevent swinging of the free end thereof intoproximity with said one terminal. i

6. A fuse device including in combination an expulsion fuse holderhaving an open end for the discharge of gases therefrom, terminalsadjacent opposite ends of the holder, a fuse link in said holderconnected between said terminals with one end of the fuse link anchoredto the one of said terminals adjacent said open end of the holder, aportionof said fuse link upon fuse link rupture being expelled from saidopen end of the holder in a manner to cause the expelled fuse linkportion to swing about its anchoring point on said one terminal, andsnubbing means -inend thereof into proximity with the other of saidterminals.

7. In a fuse device including a fuse holder adapted to accommodatetherein a fuse link and having adjacent one end thereof a terminal withmeans for securing thereto one end of a fuse link in said holder, a fuselink tensioning and retracting spring device arranged to be connectedwith a fuse link accommodated in said holder for effecting upon ruptureof the fuse link a quick withdrawal of a freed end of the fuse link fromthe holder in a manner to cause such withdrawn end of the fuse link toswing about said securing means, and an arm projecting outwardly fromsaid holder and provided at its outer end with a transversely extendingportion arranged to extend into the path of swinging of the withdrawnfuse link end to intercept the same and prevent swinging thereof intoproximity with the other end of said holder.

8. In a fuse device, a fuse holder open at one end and having a terminaladjacent the other end thereof, a conducting member secured to the fuseholder adjacent said open end thereof and having an arm projectingoutwardly from said holder, a. fuse link in the holder with one endconnected to said terminal and the other end extending out of said openend of the holder,

, means clamping said other end of the fuse link to said memberintermediate the outer end of said arm and said open end of the holder,a spring device connected with said fuse link intermediate said clampingmeans and said open end of the holder and operative upon fuse linkrupture quickly to withdraw. the fuse link from the holder in a mannerto cause the withdrawn fuse link to swing about said clamping meansin'the direction of the outer end of said arm, and snubbing means on theouter end of said arm arranged to intercept the withdrawn fuse link toprevent the free end thereof from swinging into proximity with theterminal at said other end of the fuse holder.

9. In a fuse device, a fuse holder having a terminal at one end thereof,a fuse link in saidholder with one end connected with said terminal andthe other end thereof extending out the other end of said holder, amember secured to said holder and having an armprojecting outwardlyfromthe holder adjacent said other end of the holder, terminal meansadjacent said other end of the holder including a clamp for anchoringsaid outwardly extending end of the fuse link'at a point intermediatethe outer end of said arm and said other end of the holder, and a springdevice arranged normally to tension said fuse link and operative uponfuse link rupture to withdraw the fuse link from said holder in a mannerto cause swinging of the withdrawn fuse link about said clamp andtowardsaid arm, said arm having a portion arranged to extendtransversely of the pail i 05. swinging of the withdrawn'fuse link at apoint from said clamp so as to intercept the ndrarni link.

10. In a fuse device, accommodate therein a fuse link, a member mountedon said holder-and having an arm projecting outwardly mm. the holderadjment one end of the holder, terminal means including a clamp foranchoring intermediate said one end of the holder and the outer end ofsaid arm one end of a fuse link extending from said one end from saidholder in a manner to cause swinging of the withdrawn fuse link aboutsaid clamp and Patent No. 2,155,159;

a fuse holder adapted toe link a quick withdrawal of the fuse linkBENJAMIN R HERNA NN toward the outer end of said arm, said arm having aportion arranged to extend transversely of the path of swinging of thewithdrawn fuse link for intercepting the same.

11. In a fuse device including a fuse holder adapted to accommodatetherein a fuse link and having adjacent one end thereof a terminal withmeans for seeming thereto one end of a fuse link extending from said oneend of the holder, a fuse link tensioning and retracting spring carriedby said holder in spaced apart electrically insulated relationship withsaid terminal and having means arranged releasably to engage a fuse link,at a point intermediate said securing means and said one end of thefuse holder.

12. In a fuse device including a fuse holder adapted to accommodatetherein a fuse link and having mounted adjacent one end thereof aterminal with means for securlng thereto one end of a fuse linkextending from said one end of. the holder, a fuse link tensioning andretracting spring strip, a supporting element for said spring stripclamped to said holder in spaced apart electrically insulatedrelationship with said terminal, means for securing one end of saidspring strip to said supporting element, and a hook on the other end ofsaid spring strip for quick releasable engagement with a portion of afuse link extendlng out of said one end of the fuse holder.

BENJAMIN R. HERIMNN.

October 11, 1958'.

It is hereby certified that error appears in the .printed specificationof the above numbered patent requiring correction as follows Page 5',

first column, line L T, claim5, after the. word "ruptured" insert fuselink from said one end of the holder in a; and that the said LettersPatent should be read with this correction, therein that the same mayconform to the record of the case in the Patent Office Signed and sealedthis 15th day of December, k. D. 1958.

. Seal) Henrv Van Arsdale Acting Commissioner of Patents.

